Avian Metapneumovirus Infection Rhi ...

Avian Metapneumovirus Infection Rhinotracheitis (Swollen Head Syndrome SHD) in Laying Hens

Happenings / Clinical Signs

Visibly sick birds

• Few visibly sick birds
• Usually less than 4% of the flock are affected

Egg drop

• Egg production may be affected
• Egg production drop gradually

Mortality

• Low mortality or increases gradually
• Mortality rarely exceeds 2%

Dead Birds

• Poor body fleshing condition

Head Comb Wattles Face Nostrils Sinuses Mount Beak Ear lobes

• Swelling of the Head
• Swelling of the periorbital and infraorbital sinuses

Respiratory

• Respiratory signs spread fast

• Widespread respiratory signs are usually present

Neurological /Nervous

As a result of secondary E. coli infection

• Torticollis
• Cerebral disorientation
• Opisthotonus

Neck wings breast abdomen shanks legs hocks feet joints vent skin

• Hens in lay may also present with prolapsed oviducts due to violent coughing

Shell quality

• Pale or loss of colour in brown-shelled eggs
• Misshapen eggs

The Avian metapneumovirus infection has been associated with swollen head syndrome (SHS) in chickens, which is characterized by the following clinical signs: swelling of the periorbital and infra-orbital sinuses, torticollis, cerebral disorientation and opisthotonus, as a result of secondary E coli infection. Usually less than 4% of the flock are affected, although, widespread respiratory signs are usually present. Mortality rarely exceeds 2%. The infection is associated with reduced egg production loss the shell colour and misshapen eggs.